In general, a semiconductor device, a display device and a solar cell are fabricated through a depositing process where a thin film is formed on a substrate, a photolithographic process where a thin film is selectively exposed and shielded by a photosensitive material and an etching process where a thin film is selectively removed. Among the fabricating processes, the deposition process and the etching process are performed in a substrate processing apparatus under an optimum vacuum state using a plasma.
In the depositing process and the etching process, it is required to uniformly supply an active process gas or an ionized process gas onto the substrate by a plasma discharge. However, when an integrated plate electrode or a split electrode divided into plurality is used for the plasma discharge, it is difficult to obtain a uniform plasma density in the reaction space due to various factors.